Ava Hessington, PhD. is the CEO of Hessington Oil. She was the main focus of season 3, as she was being charged with bribery and the murder of her opposers by Cameron Dennis. Though Harvey Specter was her lawyer in court, it took a great deal of resources and quite a few lawyers from Pearson Darby Specter, including all three name partners, to keep her out of jail. It was later revealed that Stephen Huntley, Edward Darby's right hand man was responsible for the murders and he was trying to set her up for it. She later sued Pearson Specter for malpractice but later Harvey convinced her to drop the case.
Ava was born to the Hessington family, who have been in the oil business for some time. Growing up, Ava knew that her father was secretly in love with Edward Darby, a close friend of the family. At the time, a lawyer and an oilman coming out of the closet would have meant career suicide, and so this remained a secret from the world. In order to be together, Ava's father and Darby would go away on vacation; when this happened, Ava would join them and pretend to be Darby's girlfriend, in order to provide cover. Because of this, Darby considers Ava to be family, which is why he worked so hard to clear Ava of all charges.
She has a PhD. in chemical engineering and petroleum exploration.